Career change at midlife and beyond is an increasingly common phenomenon, yet little is known about how such change affects the mental health of older adults. Despite the volume of research investigating the effects of contemporaneous occupational status and work conditions on mental health, few studies have attempted to link changes in the nature of one's work and disjunctures in occupational trajectories over the life course with mental health. The proposed research will examine the effects of midlife career change on two dimensions of mental health: psychological well-being and depression. The analysis uses data from the Wisconsin Longitudinal Study, a sample survey of 10,317 men and women who graduated Wisconsin high schools in 1957, and who were re-interviewed in 1964, 1975, and 1992-93. "Career change" is operationalized as the movement into one's current (or most recent) employer spell held at age 52-53, from one's previous employment spell. The goal is not simply to assess the mental health consequences of mobility trajectories or minor changes in job duties over the life course, but to examine cases where work lives take on a new direction at midlife. The central theme of this research is that the extent to which career change impacts psychological functioning may depend on the type of career change that occurs, and the context in which these changes occur. Four dimensions of career change are considered: (1) career changes accompanied by substantial shifts in the nature of job tasks and demands (e.g., substantive complexity, manipulative skill requirements); (2) the reason for career change (e.g., voluntary, involuntary, health-related); (3) whether change was lateral, upwardly mobile, or downwardly mobile; and (4) whether the change involved a movement into or out of self-employment. The analyses will also explore whether career change has unique implications for specific subdimensions of depression (depressed affect, somatic complaints, low positive affect, interpersonal problems) and psychological well-being (e.g., personal growth, and purpose in life). Gender differences in observed relationships will be highlighted.